No database selected PHP login - php

Question

Im trying to create a Login but everytime I type my credentials and click on Login, I get "No database selected"
Here is my PHP code
<?php define('DB_HOST', 'localhost');
define('DB_NAME', 'phplogin');
define('DB_USER','adminuser');
define('DB_PASSWORD','adminuser');
$con=mysql_connect(DB_HOST,DB_USER, "")
//$mysql_select_db = 'phplogin'
//or die("Failed to connect to MySQL: " . mysql_error());
//$db=mysql_select_db(DB_NAME,$con)
or die("Failed to connect to MySQL: " . mysql_error());
$ID = $_POST['user']; $Password = $_POST['pass'];
function SignIn()
{ session_start();
if(!empty($_POST['user']))
{ $query = mysql_query("SELECT * FROM phplogin where userName = '$_POST[user]' AND pass = '$_POST[pass]'") or die(mysql_error()); $row = mysql_fetch_array($query) or die(mysql_error()); if(!empty($row['userName']) AND !empty($row['pass']))
{ $_SESSION['userName'] = $row['pass']; echo "SUCCESSFULLY LOGIN TO USER PROFILE PAGE..."; } else { echo "SORRY... YOU ENTERD WRONG ID AND PASSWORD... PLEASE RETRY..."; } } } if(isset($_POST['submit'])) { SignIn(); } ?>
Where is the mistake?
Kind regards
newbie

Answer 1

You forgot to pass the variable $con as the link parameter.
mysql_select_db('database', $con) or die(mysql_error());

Answer 2

Use pdo for prevent sql injection.
You mistake this
mysql_select_db('database', $con) or die(mysql_error());
Mysql not available in php7. You can use mysqli or pdo.
$servername = "localhost";
$username = "username";
$password = "password";
try {
$conn = new PDO("mysql:host=$servername;dbname=myDB", $username, $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
echo "Connected successfully";
}
catch(PDOException $e)
{
echo "Connection failed: " . $e->getMessage();
}

Answer 3

I would really recommend you to use classes, methods and most importantly PDOs.
The use of "unescaped" mysqli is very insecure and vulnerable due to SQL injections.
Also, when storing passwords into your DB, hash them using the PHP function password_hash($password, PASSWORD_DEFAULT); This will generate a hash string that you can store in your DB.
That SignIn with the use of PDO and password_hash() and password_verify() to verify the password would look the following:
Class DataBase (DB) (db.php)
class DB {
private $error;
private $db;
function Conn()
{
try {
$this->db = new PDO('mysql:host=localhost;dbname=phplogin;', 'adminuser', 'adminuser'); //second adminuser is password
return $this->db; //Returns PDO object
}
catch(PDOException $ex){
return $ex->getMessage();
}
}
}
Your login.php (login.php)
require_once('db.php');
$db = new DB(); //Create instance of DB class
$conn = $db->Conn(); //Call Conn() method of DB class
$username = $_POST["user"];
$password = $_POST["pass"];
$statement = $conn->prepare("SELECT * FROM phplogin where userName = :user");
$statement->execute(array(":user"=>$username)); //For :user in SQL query it enters the username you entered in the login form (bind param)
$row = $statement->fetch(); //Returns the row from DB
//password_verify() checks if the password you've enteres matches the hash in the DB
//$row["pass"] is the hash you get returned from the SQL query aboth
if(password_verify($password, $row["pass"])){
return true; //Or echo "success"
}
else{
return false; //Or echo "Wrong username/password"
}
I hope I was able to help you :)